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On monster dovetails, and embracing the fear

Setting the depth of cut with blue tape and a small combination square

The staked work table build is pretty straight forward, and on the whole very enjoyable. I mean, if you can’t enjoy octagonalisation that means you’re already dead inside, right? But the one stage of the build which has given me the fear is cutting the sockets for the dovetailed battens. Although the task itself is not that complicated, it really is a one shot deal, with very little opportunity to remedy any errors. The sockets need to match the profile of the battens, and a tight fit is necessary to restrain any seasonal movement of the top. Because the sockets run the full width of the top, any gaps at the front of the table will be extremely noticeable. It is probably no surprise that the opportunity to ruin the top was something that loomed large in my mind when I stepped up to the bench to start cutting.

My off-hand keeps the saw cutting against the side of the batten

When cutting the sockets you use the battens to guide the saw, and providing you make the cuts with care, this method should ensure that the socket matches the profile of the battens. I had originally made the battens over length by a couple of inches, and I decided to leave them at this length when cutting the first wall of each socket as this would provide a greater surface area for the saw to register against. As the front end of each batten was square, I was able to clamb the battens in place flush with the front edge of the table top, making sure that they were parallel to the ends of the top. I decided to cut the innermost edge of the sockets first, although there is no real difference in which side you cut first – the main thing is to be consistent as this helps to avoid mistakes.

When the blue tape hits the surface of the table, stop cutting

As I’ve written about before, I have a (ahem) healthy nest of saws. I spent some time considering which saw would be most appropriate for these cuts, and decided to go with the Roubo Beast Master by Bad Axe Tool Works. Although my Beast Master is filled rip (and this is a crosscut operation), it had a number of significan attributes which I wanted for cutting the sockets (and not just because Mark promises it cures baldness). The robust saw plate meant that the saw would be able to withstand being pushed across 24″ of hard maple without suffering undue strain, and would hug the batten so as to cut the right slope angle. Finally, the 5″ depth of plate under the saw back means that the handle would not foul on the batten, as would happen with a shallower saw.

The Beast Master leaves a crisp kerf

So, with my saw selected and the battens clamped in place, it was time to be brave and start slicing up the table top I’d spent previous weeks preparing. When making the cut, my off-hand pressed the saw plate into the batten just above the toothline, while I pushed the saw forward with the open palm of my on-hand in order to avoid tilting the saw or twisting it away from the batten, only wrapping my fingers around the handle to pull the saw back for the next stroke. Once the kerf was established, the saw cut down to depth smoothly and rapidly, and there was minimal chipping out on the exist side of the cut despite using a rip saw (all of the cuts were made from the front edge of the table towards the rear edge so that any chipping out would be on the back edge). I marked the depth of cut on the saw plate with blue painter’s tape, and once the tape hit the surface of the table I stopped cutting. The Beast Master left a crisp and clean kerf across the table.

Trimming the battens to length

Because the battens are angled, determining the location of the second side of the socket takes a bit of lateral thinking, and Chris covers this very clearly in the book. I cut the battens to length using a 16″ hybrid filed Bad Axe tenon saw, and used the offcuts to mark off the second side of each socket, allowing for the set of the Beast Master. The process for the second cut was the very much the same as the first, following which I put the battens aside while I cleaned out the waste. I hogged out the majority of the waste with a 3/4″ chisel and mallet, working from both ends into the middle of the table to avoid spelching. Once I was close to the bottom of the saw kerfs, I switched to a large router plane to clean up the bottom of the socket.

A chisel and mallet makes short work of cleasring out the socket

With the sockets cleaned up, it was time for the moment of truth, and I fitted the battens using a 1lb lump hammer to drive them in. The fit was good and tight without being too much of a squeeze, and with no real gaps at the front edges, which is exactly what I was looking for. As a final step, I took two fine shavings from the middle of each side of both battens, just to ease the fit a little bit (but without reducing the efficacy of the batten).

1 thought on “On monster dovetails, and embracing the fear”

It fit right off the saw? That’s amazing! When I made this table I had a fair amount of planing to do to make the batten fit. If I make another one I might consider doing a tapered sliding dovetail.i made a few that way for some cutting boards recently, and found them a bit easier to fit by hand, since a shaving or two too many on a tapered sliding tail is no problem as long as the batten was, oversized to begin with. Just tap it in a but further and its tight. The only thing I I’d worry about is how wood movement would effect it. If I glued only the large side of the tapered batten, and the table expands, will it become loose enough to wiggle on the smaller side of the taper? Or would expansion of the batten itself take up any amount of wiggle caused by expansion across the slot?